| 摘要 |
<p>PURPOSE:To suppress the abrasion of a motor brush or the like and extend the life of an electric motor by providing a revolving speed sensor on the electric motor, and controlling the applied voltage to the electric motor so that the motor revolving speed is not increased to the necessary maximum revolving speed or above. CONSTITUTION:A pinion shaft 3 is rotated by the driving force of an electric motor 7 to move a rack shaft 4, and the steering force is power-assisted. A revolving speed sensor 16 is connected to the electric motor 7, and the detected motor revolving speed is fed back to a control device 15. When the detected motor revolving speed is smaller than the necessary maximum revolving speed, the control device 15 increases the applied voltage to hold the motor revolving speed at the necessary maximum revolving speed. When the detected motor revolving speed is larger than the necessary maximum revolving speed, the control device 15 decreases the applied voltage to hold the motor revolving speed at the necessary maximum revolving speed. The durability of the motor 7 is improved.</p> |
